Effect of Induced Mechanical Leaf Damage on the Yield and Content of Bioactive Molecules in Leaves and Seeds of Tepary Beans (Phaseolus acutifolius).

Growing interest has recently been shown in Tepary beans (Phaseolus acutifolius) because they contain lectins and protease inhibitors that have been shown to have a specific cytotoxic effect on human cancer cells. Bean lectins offer protection against biotic and abiotic stress factors, so it is possible that mechanical foliar damage may increase lectin production. This study evaluates the effect of mechanical stress (foliar damage) on lectin and protease inhibitor content in Tepary beans. Seed yield was also analyzed, and phenolic content and antioxidant capacity (DPPH and TEAC) were determined in the leaves. An experimental design with random blocks of three treatments (T1: control group, T2: 50% mechanical foliar damage and T3: 80% mechanical foliar damage) was carried out. Mechanical foliar damage increased the amount of lectin binding units (LBUs) fivefold (from 1280 to 6542 LBUs in T3) but did not affect units of enzymatic activity (UEA) against trypsin (from 60.8 to 51 UEA in T3). Results show that controlled mechanical foliar damage could be used to induce overexpression of lectins in the seeds of Tepary beans. Mechanical foliar damage reduced seed production (-14.6%: from 1890 g to 1615 g in T3) and did not significantly increase phenolic compound levels in leaves.

Comparative histological and immunohistochemical study of ameloblastomas and ameloblastic carcinomas

BACKGROUND: This study aimed to compare the histological and immunohistochemical characteristics of ameloblastomas (AM) and ameloblastic carcinomas (AC). MATERIAL AND METHODS: Fifteen cases of AM and 9 AC were submitted to hematoxilin and eosin (H&E) and immunohistochemical analysis with the following antibodies: cytokeratins 5,7,8,14 and 19, Ki-67, p53, p63 and the cellular adhesion molecules CD138 (Syndecan-1), E-cadherin and β-catenin. The mean score of the expression of Ki-67 and p53 labelling index (LIs) were compared between the groups using the t test. A value of p < 0.05 was considered to be statistically significant. RESULTS: All cases were positive for CKs 5, 14 and 19, but negative for CKs 7 and 8. CKs 5 and 19 were positive mainly in the central regions of the ameloblastic islands, while the expression in AC was variable in intensity and localization. CK14 was also variably expressed in both AM and AC. Ki-67 (P=.001) and p53 (P=.004) immunoexpression was higher in AC. All cases were positive for p63, but values were higher in AC. CD138 was mainly expressed in peripheral cells of AM, with a weak positivity in the central areas, while it was positive in most areas of ACs, except in less differentiated regions, where expression was decreased or lost. E-cadherin and β-catenin were weakly positive in both AM and AC. CONCLUSIONS: These results shows that Ki-67, p53 and p63 expression was higher in AC as compared to AM, suggesting that these markers can be useful when considering diagnosis of malignancy, and perhaps could play a role in malignant transformation of AM. Pattern of expression of CKs 5 and 19 in AC were different to those found in AM, suggesting genetic alterations of these proteins in malignant cells. It was confirmed that CK19 is a good marker for benign odontogenic tumors, such as AM, but it is variably expressed in malignant cases

Oral perineurioma: clinicopathologic features from two cases and review of literature.

The present study reports two cases of oral perineuriomas, including a clinicopathologic review of the 39 published cases (17 intraneural and 22 extraneural perineuriomas) in the English language literature. In the first case, the tumor occurred in an 84-year-old male as a painless, asymptomatic, 20-mm submucosal nodule on the right lower mucobuccal fold near to the premolar area. In the second case, a 46-year-old female presented with a painless, 25-mm, slow-growing, fibrous, pedunculated nodule on the right buccal mucosa. In the first case, the tumor was composed of spindle cells arranged in a storiform pattern, classified as intraneural perineurioma; and in the second, it was an extraneural perineurioma, showing a whorled myxoid stroma. Immunohistochemical analysis confirmed the diagnosis by showing positivity for vimentin, EMA, and Glut-1 in case 1 and EMA, Glut-1, Claudin-1, and CD34 (focally) in case 2. Complete surgical removal was performed for both tumors, and there was no evidence of local recurrence after a long-term follow-up.